Apparatus fpr wireless telegraphy.



No. '763,772 PATENTED JUNE 28, 1904. G. MARCONI.

APPARATUS FOR WIRELESS TELEGRAPHY. APPLICATION FILED No'v.1, 1900.

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El 1111 Jl] II Il 1/ /l/ /11/ Q Si J3 GUGLIELMO AR`coNl, B5

UNIT-ED STATES GUGLIELMO'MARCUNI, '0F LONDON,l

ENeL-ND, ASSIGNOR 'o MAROONrs WIRELESS TELEGRAPH COMPANY;l LIMITED, OFv LONDON, ENGLAND.

lAPrnFm-rus son wml-:LESS .TELEGRAPl-lv.

srncmea'rron forming pm ofwfn raient No. 763,772, 'dma :une es, 1904.

' Appleman anarmmw 10,1900; som un'. aaolo. un man.)

To (till whom itfmay concern.:

Be it known that I, .GUGLIELMO MARcoNI, electrician, a subject of the King of Italy; residing and having a post-ol'lice address at 18 Finch Lane,.Threadneedle street, in J the city of London, England, have invented certainynew and 'useful Improvements in Apparatus' for Wireless Telegraphy, of which the following is a specitication.

My invention relates to apparatus forcemmunicating .electrical signals without wires andby means of Hertz oscillations or'electric waves; and the object of the invention is to increase the eiiiciency of the system and .to provide new and simple means whereby oscillations or electric wavesfrom a transmittingstation may be localized when desired at any one selected receiving station or stations out of a group of several receiving-stations.

. In my prior United States patent No. 586,193 (Reissue No. 11,913, dated June 4, 1901) I have shown and described the combination at 'a transmitting-station of an oscillation pro-" ducer, such .as an induction-coll, having one end of its secondary coil connected to one contactof la spark-producer and to the earth and having the other end of the said secondary connected to the opposite contact of the sparkproducer and to a vertical wire or elevated l plate, and I have further shown at a receiving'` station an imperfect contact connected in circuit with a vertical receiving-wire and with the earth. According to the present. invention the system includes at the transmittingstation the combination, with an oscillationtransformer of a kind sui-table for the transformation of very rapidly alternating cu'rrents, of a persistent oscillator, and a good radiator, one coil of said vtransformer being connected between the aerial wire or plate and the connection thereof to earth, while the other coil of the transformer is connected in circuit with a condenser, a producer of Hertzian osclllatons or electric waves shown in the formloifa-spark-produeenand an induction-coil (constituting the persistent oscillator) controlled' by a signaling' instrument. 'Thei 'complete' system .also includes at a receiving-station an oscillation-transformer one coil whereof is included between the aerial receiving-'wire and earth, constituting'a good absorberfof electrical oscillations, while a device responsive. to electric waves, such as -an 4imperfect contact or a device for operating the same, is ineluded in a circuit with the other coil of saidv transformer. Th'esystem also requires as essental elements thereof the inclusion in the vlines (at both'stations) from the aerial' conduct'or to the earth'of variable inductances and the use' at both stations of means for varying or adjusting the inductance of the twoeircuits at each station to accord-with each other. By Nthis arrangement of apparatus I amable to .secure a perfet tuning of the .apparatus at a transmitting-station and at one or more of a number of receiving-stations. j

Referring to the accompanying drawings, Figure 1 indicates diagrammatically the arrangement of apparatus at a transmitting-station. Fig. 2 indicates diagrammatieally. the arrangement 'of apparatus at a receiving-station. Figsr3 and 4 are views, plan and side,

of the preferred form'of transformer-,at the4 Figsz, 6, 7', andl 8 are.

.transmitting-station. diagrammatic views of forms of transformers at thelreceiving-station. y v.-

The transmitting-station is provided under` .my present invention wit a source a of eurrent electrically connectedin circuit with the. primary of an` induction-coil c and with a circuit-closing key b or otherwise controlled b y a si gnalin g instrument. 'In the second ary circuit o said v induction-coil vthe spherical terminals or other contacts of aYspark-,producer or otherelectric-wave or oscillation producer are included with a shunt therefrom, in

which shunt is included the primary coil d of an oscillation-transformer, such as d. A condensere, preferably one provided with two Y telescoping metallic tubes separated by A,a di# electriqand arranged to readlly van' the capacity by 'being slid upon each other, :is-inf eluded in one connection from the lnductloncoil to the transformer-windmg d, The secv ondary coil d' of the transformer is connected p (ut one end) to the earth-E and at ltslotherendl to a vertical wire A or an elevated plate f.

Itj-is obvious' that instead of the induction-A idly radiated in 647,008, 647,009,and 668,315, capable of bei coil and associated parts f or producing the electric waves or oscillations I may use any other proper means for producing such Waves or oscillations-such, for instance, as a generator of alternating electric currents.

The illustrated arrangement of parts at a'. transmitting station enables much more energy to 'be imparted to the radiator-f, the

character that if electromotive llforce is sud-I denly applied to it and the current then cut oelectrical` oscillations are set up in the circuit which persist or are maintained for along time-in the primary circuit and use a good radiator-z'. e., an electrical circuit which very quickly imparts the energy of electrical oscillations te the surrounding ether in the form of waves-inthe secondary circuit.

In operation the signaling-keyr 6 is pressed, and this closes the primary of the inductioncoil. Current then rushes through the transformer-circuit and the condenser a is charged and subsequently discharges through .the spark-gap. If the capacity, thel inductance, and the resistance of the circuit ,are of suitable values, the dischargeis oscillatory, with the result that alternating currents of high frequency passthrough the primary of the transformer and induce similar oscillations in the secondary, these oscillations being rapthe form of electric waves by the elevated conductor. i y

For the best results and in order to effect thesele'ction of the station or stationswhereat the transmitted oscillations are to be localizedI include in the open secondary circuit of the transformer, and preferably between the radiator f and the secondary coil d', an inductance-coil g, Fig. 1, having numerous coils, and the connection is such that a greater or'less number of turns of the coil can be put in use, the proper number being ascertained by experiment. p At the receiving-stations employing my present invention I prefer to use a receiver such as those described in my several United States Patents, NOS. 586,193, 627, 650, 647,007,

ing affected by electrical waves or oscillations of high frequency.

As a responder to electric waves I may use l at the receiving-station any of the now wellknown forms of such devices, such as those which depend for their action on the reduction of the resistance of a metallic microphone by the action of electric waves or fcoherers,

one form of which is disclosed in my Patent No. 586,193, or I may employ one whichdepends for its action on the increase ofthe resistance of the device under the iniiuence of the electric waves or vanticoherers, such as described by Branlyin. La Lumjere Electrique of June 13, 1891, or I may use those which depend upon the action of an electric thence to earth E.- In a shunt around said' primary j' I usually place a condenser L, preferably similar in construction and operation to the condenser e. An inductance-coil g' of variable inductance is interposed in the primary circuit of the transformer, being preferably located between the cylinder f and the coil j', andthe inductance of said coil may be adjusted in accordance with the method described by me in my Letters Patent of the United States No. 676,332 to harmonize with the inductance of coil g at the transmit.- ting -station, Fig. 1 of the accompanying drawings, or with that of the coil or coils at one or more of the transmitting-stations included in the communicating system.

The secondary coil j of the transformer is wound in two parts, preferably as described in my United States Letters Patent No. 668,315, dated February 19, 1901 and the outer ends of said coil' are connected in certain cases through one or more interposed inductancecoils gznpreferably of variable inductance, with the terminals of a coherer T or other detector of electrical oscillations. The inner ends of the split secondary coil are connected to the plates of a condenser js. -A condenser is sometimes included in. a shunt around the detector T. B is a battery, and R a relay connected to the condenser 7" and controlling a telegraphing instrument or a printing device. c and c are choking-coils preventing oscillations from-'the secondary j running into the battery-circuit, and thereby confining them to the wave-responsive device.

The capacity and self-induction ofthe four circuits-z'. e., the primary and secondary circuits at the transmitting-station and the the receiving-stations inl a communicating system-are each and all to be so independently adjusted as to make the product of the self-induction multiplied by the'capacity the, same in each case or multiples of each otherthat is to say, the electrical time periods' of the fourcircuits are to be the same or octaves of each other.`

In employing this invention tollocalize the IOO IIO

izo

primary and secondary circuits at anyone of other stations.

millimeter of jute, making a -total thickness` seventhlayer, thirty-four turns; eighth layer,

reame i B transmission of intelligence at, one of several receiving-stations the time period of the circuits at each of the receiving-stations is so arranged as to be different from those of the If the time periods of the circuits of the transmitting-station are 'varied until they are `in resonance with those of one of the receiving-stations, thatone alone of all of the receiving-stations will respond,provded that the distance between the transmitting and receiving stations is not too small.

The adjustment of the self-induction and capacity of any or all of the four circuits can be made in any convenient manner and employing various arrangements of apparatus, those shown and described herein being:l` preferred. In practice I have found the following preferred detailsof arrangements of apparatus to work well: The aerial conductors A at all stationsand the conductor for the transformer-,windingsatthe receiving-stations l are 'composed of seven strands of copper wire .889 millimeters in diameter. The transformer at the transmitting-station may be of any of the following forms:

` 1. Around a block or core d', preferablyla square block-say .17v meters wide-of insu# lating material is wound a primary coil. d in 'length ..946 meters, while the secondary d' consists of two turns or squares, one lying on each side of the primary. See Figs. 3 and 4.) The insulation of both primary and secondary consists of 1-.25 millimeters of rubber and one of 2.25 millimeters.

2. A transformer in all essentialrespecte similar to-1, but with a primary of 1.93 me# ters and the core'or block on which both primary and secondary are wound, is .3048 meters wide.

3. A transformer having'a cylindrical core" 10.16 centimeters in diameter and with aA primary having ten turns wound thereon; over this, but separated by two millimeters of paper orother insulant, the "secondary, also of ten turnsf' Various forms of transformers,.&e., which may be ,employed b me are describedin my British Patent No'. ,777 of 1900.

The inductance-coils g and g are `preferably` of copper Iwire 6.25 millimeters in diameter, wound. on a cylinder 10.64 centimeters in diameter,.with an interval of 2.28 milli-4 meters between adjacent turns. The inductance-coils g at the receivin'gfstation are preferably of silk-covered' copper wire .'19 millimeter diameter wound upon cylinders 3.7 centimeters in diameter.

Various forms of nducti -coils j' j' may' be used. Figs. 5, 6, 7, an 8 show details of different forms. "The ligures show diagram-l `matically .greatlyenlarged longitudinal sec'- `tions not strictly to scale. Instead of showing the section ofeach coil or layer of wire as a longitudinal row of dots or small circles,

as it would actually appear, it is for simplicity hown as a continuous longitudinal straight me. Referring to Fig. 5, the primaryj' preferably consists of 3.046 meters of silk-covered copper' wire, say, and seventy-one millimeters in diameter wound in one layer on a core of ebonite or other insulating material 2.9 centimeters in diameter. Insulating material is wound over and on each side of this, so as to make a cylindrical core', say, 3.13 centimeters' in diameter, on which is wound the secondary, each half of which consists of 6.4 meters of silk-covered copper, wire .19 millimeterin diameter joined to 13.41 meters of silk-covered copper wire .37 millimeter in diameters wound in the same sense as the vprimary,-the

thinner wirebeng over the primary and the thicker being beyond the ends thereof. -A

The form of-induction-col shown in Fig. 6

has a primary of one hundred turns of copper wire .037 centimetersm diameter wound on a core j (2.9 centimeters in diameter) with a single silk covering and coated with paraliin wax. The secondary j is of copper wire .019

' in diameter, insulated witha single silk covering, and is ,wound over the primary, commencing in the middle and in the same way as the primary. Each half of the secondary is in layers ofthe following nu ber of turns: first layer, seventy seven tu s; second layer,

forty-nine turns; vthird layer, forty-six turns;

fourth layer, forty-three turns; fifth layer, forty turns;- sixth layer, thirty-seven turns;

thirty-one turns; ninth layer, twenty-eight turns; tenth layer, twenty-five turns; eleventh layer, twenty-two turns; twelfth layer, nineteen turns; thirteeth layer, sixteen turns; fourteenth layer, thirteen turns; fifteenth layer, ten turns; sixteenth layer, seven turns; and

ICO

seventeenth layer, three turns, making fivehundred turns in all.

A third form' of. induction-coil (shown in Fig. 7) has a primary of 3.048 meters of silkcovered copper wire .19 millimeter in 'diameter and asecondary'of 30.48 meters of silkcovered copper wire 1 millimeter in diam` yeter wound in one layer on a core four centimeters in diameter, the primary being in one layer outside of the secondary.

- The fourth f orm'of induction-coll is shown in Fig. 8. j Its primary consists of 3.048 meters of silk-covered copper wire .37 millimeter in diameter wound on a. core 2.9'centimeters indiameterand inserted in a tube j* 'of four centimeters external' diameter, on which is wound thesecondary of 27.432 meters of silk-covered copper wire .12 millimeter in diameter, the break a't the middle of .the secondary being 'over the middle of the'A primary. Other forms of transformers which may be ,employed vbyme are described and claimed in my British Patent No. 7 ,777 of 1900.

' 'each of the coils Q and g and by also includ- 'e is varied the two stations -to-skilled l'What l claim ls- 1 transmitting-station table being of course used in connection with those tune 1n the receiving-stati opposite the same onl table:

` Transformer I Inductance number of Ca *it Len t 'Iuge' Aem conduclm," d d. turns of g included. "mlcrolc e. maagd-.k in No. 1. adm motors of oablo. No.1. Nono.-

a No.2. 'do. No. 1; 4s .oleane 4 No. d0. No. 8. None. .(04112 8 No.4. do. No.. 2. 10o .016849 4 No.5. Zinc lindernill-M me- Noj... n 1 i ters ong, 1.524 meters o e wo 125 in diametenand hoisted 8.08 meters above groun v No. o. 80:48 meten of cable. no'. s. A None. .wom 4 Recevf'fng-Stat'iwa.

Capacity in microfarads ot- Inductance `Introduced in- Tune Inductionl con. Q

I h" Number of turns. a" No 1. No. 1. omitted. omitted. None. None. No. 2. No. 1. omitted. 4s' Nono.

No. 8. No. 2. .004e Omitted. Up 1.0.21 may bein- None.

, serted. `No. 4. no. a .001s omitted. 10o 2 nous of 15.24 mefom at each end ot secondary. No.; No. se omitted. I omitted. Node. Nono. No. s. NoV 4. omitted. omitted. None. None.

It will be observed that'both the transmitter and the receiver are the same fortunes 1 and 2 and that when the capacity of the condenser \can he brought into tune byincluding forty-five turns of each g 1g' and by introducing a condenser afof small capacity in parallel with the coh'erer T, Similarly the transmitter andreceiver arethe same for tunes 3 and 4, and when the. capacity of eis varied the stations are tuned by` including one hundred turns of ing the coils g. While I have vherein shown and described details of construction and of arrangement found by me to be useful, yet I do not Wish to be understood as confining my claims theremy Ainvention will readily suggest themselves 7 persons.

`1 .A t a stationemployed in a wireless-telegraph system, ing an inducti which through-a me oscillations o circuit electr inclu 11 Opel] wally connected with the oscillaance included in theo as and for the 2.- At a statio graph system, tor, a variable conductor; ally connected cuit wit the purposedescn graph system, prisingan indu cuit of which in through oscillatio pen circuit, substantially purpose described i n employed in a wireless-telean oscillation-receiving conducinductance connected with saidr a wave-.responsive device electrical station employed in a wireless-telea signaling instrument vcoin-- ction-coil, the' secondary circludesa condenser discharging a sgnalinginstrument comprison-coil, the secondary circuit of des a condenser discharging ans which automatically causes fthe desired frequency;

.with said conductor and in cira'condenser, substantially as and for a means which automatically causes ns ofthe desired frequency, and the;l

primary stantially as and for a system of telegraphy by oscillations of high frequency,

- which automatically causes tion thereto,

'cuits connected with 'mama circuit of which inc ludes a generator; means for varying-the primary circuit; an

open circuit electrically oonnec with the oscillation-producer aforesaid, and a variablel inductance included the open circuit, subthe purpose descri 4. In a system of syntonic wireless telegraphy, a circuit so arranged as to forma-persistent oscillator, a circuit so formed as to constitute a good radiator in inductive relameans for inducing in the oscillatpr-circuit electric undulations of a predetermined period, and means for attuning the natural period of vibration of each of said circuits to the period of the undulations so iu- 5. An element o f an apparatus employed 1n electric waves or comprising a conductor elevated' at one' end and connec to capacity atthe other endysaidconduetor includingavariable inductance and an element. having appreciable capacity, g

6. At a transmitting-station employed 1n a wireless-telegraph system, the. combination of atransformer whose secondary is connec to an open circuit including a radiating-con ductor at one end and capacity at the other end, and whose primary is`connected to a condenser-circuit discharging through a means l oscillationsof the and means for adjusting each ofthe two cirtransformer to bring substantially desired frequency, the oscillation period of the them into accord with each other,

as described.

' diator o f such waves or oscillations,

'for varying at will the-.natural period bration of the said circuit. L 8. At a transmitting-station 7. An element of.l an apparatus employed in a system of telegraphy by electric waves or oscillations ofhigh frequency, comprising anopen circuit so arranged asl to constitute a raand means of vi employed in ay wireless-telegraph system, the combination of a transformer Whose secondary is con nected to an open circuit including a radiating-conductor at one end and capacity at the oscillations ,of the desired frequency', tially as described 55 other end, a variable inductance being inluded in said circuit, and 'whose primary is connected to la condenser-circuit discharging through ameans which automatically causes substan- 9. `'At atransm1tting-station employed in a f wireless-telegraph systemthe combination Aeluded in vconnected f'- denser and with a of a transformer whose secondary is connected to an open circuit including a radiating-conductor at one end and capacity at theM other end, a variable inductance beinginsaid circuit, and whose primary is 'in serieswith an adjustable conmeans which automatically oscillations of the desired frequency,

substantially as described. l.

*. ondary vof the induction-coil; the

' to an inductance, and

end, a wave-responsive 1'0."A system of wireless telegraphy, ,.in

- whichl the transmitting-station and thereceiving-statign each contains an oscillation transformer, ne circuit of which is an open'cir- -cuit 'and the other'a closed circuit, the two circuits at each station being in nancel with each other and in electrical resonance with thecircuits at the other station, sulistantiallyas described.

. A1'1. In apparatus 'for communicating electrical signals, the combination, with an oscillation-transformer, ata transmitting-station,A of an inductioncoil;.an electric circuit containing the secondary of said coil, a condenser and the primary coil of the oscillation-transformer; a producer of electric .waves of high frequency electrically connected induction-coil; a signaling instrument in -circuit with the primary of the secondary coil of the oscillation transformer electrically connected, at one end to capacity and, at the other end,

an aerial conductor connected to the inductance, substantiallyas and for the purpose described.

12. In apparatus for communicating electrical signals, the combination, with an oscil'- lation-transformer, at a transmitting-station; of an induction-coil; an electric circuit containing th'e secondary of the said coil, a conelectrical resowith the secdenser and the primary coil of the oscillationtransformer; a producer o f electric waves of hlgh frequency connected with the secondary of the induction-coil; a `signaling instrument in circuit with the primary of the inductioncoil; the secondary' coil of the oscillation` IOC transformer electrically connected,at one end,

Wto capacity and, at the other end, to a variable inductance, and an aerial conductor connected -to the variable inductance, substantially as and for the purpose described.

13. At a receivi g-station ,employed in a wireless-telegraph s 1stem, the combination of an oscillation-tran former, an open circuit connected with one coil of .said transformer, said circuit including an oscillation-receiving conductor at one end and capacity at the other end, a variable inductance being included in said circuit, f a wave-responsive device 'electrically connected with the other winding of the oscillation-transformer, and a 'condenser lin circuit with the Wave-responsive device, substantially as described.

.14. At a receivingtation employed in a wireless-telegraph system, the combination of an oscillation -'transformer, an open circuit connected with one coil of said transformer,

said circuit including an oscillation-receiving conductor at one end and capacity at the other' device electrically connected with `the othenwinding of the oscillation-transformer, and means for adjusting the two transformer-circuits'n electrical resonance with eachother, substantially as de- 15. At a "receiving-station employed in a wireless-telegraph system, the combination of an oscillation-transformer, an opencircult connected with one Vcoil of 'said transformer, said circuit including an oscillation-receiving conductor at one end and capacityatthe other end, a condenser located in said circuit be- 'tween the coil and the capacity, a wave-responsive device electrically connected with the other winding of the oscillation-transformer, and means for adjusting the two transformercircuits in electrical resonance with each pther, substantially as described.

16.l At Va receiving-station employed in a wireless-telegraph system, the combination of an oscillation-transformer,anopen circuit connected with one coil of said transformer, said circuit including anoscillaton-receiving conductor at one endand capacity at the other end, an adjustable condenser in a shunt connected with the open circuit andaround said transformer-coil, .a wave-responsive device electrically connected' with the other coil of the oscillation-transformer, and means foradjusting the two transformer-circuits. in electrical resonance with each other, substantially asfdescribed.

A wireless-telegraph system,

17. At a receiving-station employed in a the combination of an oscillation-transformer,an open. circuit connected with one coil of said transformer, said circuit including an oscillation-receiving conductor at one end and` capacity at thel other end, a wave-responsive device electrically conn'ected with the other winding of the oscillation-transformer, and means included in 'each of said transformer-circuits, for adjusting said circuits in electrical resonance with e h other, substantially as described. T-

18. At a receiving-station employed in a "wireless-telegraph system, the combination of -nected with circuit including an oscillation-receiving cony an oscillation-transformer,an open circuit conone coil of said transformer, sald end,-a variable inductance being included in said open circuit, a waveresponsive device' electrically connected with the, other winding of the oscillation-transformer, and avariable inductance included in circuit with the waveresponsive device, substantially as described.

19. In a system of wireless telegraphy, the combination at a receivingstation, of an oscillation-transformer; an open circuit comprising, in part, an aerial conductor connected with one end of the primary coil of the oscillation transformer; a connection from the other end of said coil to capacity; a variable inductance in said open circuit;and electrical connections from 'the secondary coil of the oscillation-transformer te a receiving instrument, battery, condenser, wave-responsive device and a variable inductance, substantially as and for the purpose described.

20. In a system ofwireless telegraphy, a transmitting-.station containing an oscillationtransformer, the primary of which is connected to a condenser-circuit discharging through a spark-gap which automatically causes electric waves of the desired frequency, the secondary of said transformer connected to an open circuit including a radiating-conductor, and with a capacity and a coil for charging the condenser aforesaid; a receiving-station con- Ytaining an oscillation-transformer, the pri mary of which is connected with an oscillation-receiving conductor and with a capacity, a wave-responsivedevice connected with the secondary of said transformer, and a receiving instrument connected with the wave-responsive device, all in combination with means for` bringing the four transformer-circuits, two at each station, inte electrical resonance with each other, substantially as described.

-V GUGLIELMO MARCONI.

Witnesses:

R. B. RA'NsFoRD, "G. F. WARREN. 

